U.S. patent application number 14/526609 was filed with the patent office on 2015-02-26 for internal inspection of machinery by stitched surface imaging.
The applicant listed for this patent is Siemens Energy, Inc.. Invention is credited to William D. Clark, Joshua DeAscanis, Clifford Hatcher, JR., Forrest R. Ruhge.
Application Number | 20150054939 14/526609 |
Document ID | / |
Family ID | 52480002 |
Filed Date | 2015-02-26 |
United States Patent
Application |
20150054939 |
Kind Code |
A1 |
DeAscanis; Joshua ; et
al. |
February 26, 2015 |
INTERNAL INSPECTION OF MACHINERY BY STITCHED SURFACE IMAGING
Abstract
A method of generating a comprehensive image (87) of interior
surfaces (78, 80) of machine components such as a gas turbine
combustor basket (59) and transition duct (34) by digitally
stitching together multiple photographs (82) thereof, and analyzing
the comprehensive image by contouring (91, 95A-B) of colors and
shadings thereon, and quantifying and tracking aspects of the
contours (A, B, C) over time for indications of degradation (89) of
the interior surfaces. A scope (58) may be inserted into a port
(56) in the combustor with a camera (72, 74) in a rotatable end
(70) of the scope for obtaining a circumferential set (84) of
photos at each axial position along a length of the combustor and
transition duct. A 3D surface scanning device (76) in the scope may
define the geometry of the interior surface for 3D photographic
modeling thereof providing a virtual walk-through inspection.
Inventors: |
DeAscanis; Joshua; (Oviedo,
FL) ; Clark; William D.; (Orlando, FL) ;
Hatcher, JR.; Clifford; (Orlando, FL) ; Ruhge;
Forrest R.; (Orlando, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Siemens Energy, Inc. |
Orlando |
FL |
US |
|
|
Family ID: |
52480002 |
Appl. No.: |
14/526609 |
Filed: |
October 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13972000 |
Aug 21, 2013 |
|
|
|
14526609 |
|
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|
Current U.S.
Class: |
348/82 ;
382/141 |
Current CPC
Class: |
G06T 2207/30136
20130101; G01M 15/14 20130101; G01N 21/954 20130101; G02B 23/2484
20130101; F01D 21/003 20130101; G01M 15/02 20130101; H04N 2005/2255
20130101; G02B 13/06 20130101; G06T 2207/20221 20130101; G06T
7/0004 20130101; G06T 2207/10004 20130101 |
Class at
Publication: |
348/82 ;
382/141 |
International
Class: |
G01M 15/14 20060101
G01M015/14; G06T 7/00 20060101 G06T007/00 |
Claims
1. A method of inspecting an interior surface of a component of a
gas turbine engine comprising: inserting a scope into an inner
portion of the component without removing the component from the
engine; obtaining a first set of circumferential photographs around
a circumference of the interior surface at a given axial reference
position therein with a camera on a distal end of the scope; and
digitally stitching the first set of photographs to form a stitched
view of the interior surface at the given axial reference
position.
2. The method of claim 1, further comprising; removing a pilot fuel
nozzle from a pilot fuel port of a combustor installed on the gas
turbine engine; inserting the scope into the combustor via the
pilot fuel port; and rotating the camera on the distal end of the
scope over 360 degrees at the axial reference position.
3. The method of claim 1, further comprising: obtaining further
sets of circumferential photographs at respective further axial
reference positions; stitching the first and further sets of
circumferential photographs of the interior surface to form a
comprehensive image of the interior surface; and determining a
condition of the interior surface by analysis of the comprehensive
image for indications of use and degradation of the interior
surface.
4. The method of claim 3, further comprising: creating a set of
intensity contours on the comprehensive image by computerized
contouring of colors and shadings in the comprehensive image, and
quantifying the indications of use and degradation of the interior
surface by computer analysis of the set of intensity contours.
5. The method of claim 4, wherein the quantifying comprises
computing an area within each contour, computing gradients and
overlaps of the contours, and computing a shape aspect of each
contour.
6. The method of claim 3, further comprising defining a
three-dimensional geometry of the interior surface by scanning the
interior surface with a 3D surface scanner in the distal end of the
scope, and digitally modeling the interior surface in three
dimensions by mapping the comprehensive image onto the
three-dimensional geometry of the interior surface creating a
digital visual model of the interior surface in a computer for
interactive viewing.
7. The method of claim 6, further comprising: creating a degree of
roughness contour on the comprehensive image by computerized
contouring of a roughness of the interior surface defined by the 3D
scanner, and further quantifying the indications of use and
degradation of the interior surface by computer analysis of the
degree of roughness contour.
8. The method of claim 3, further comprising mapping and projecting
the comprehensive image onto a three-dimensional engineering model
of the interior surface, creating a digital visual model of the
interior surface in a computer.
9. The method of claim 4, further comprising indicating an alert
status by computerized flashing of one of the contours on the
comprehensive image.
10. A method of evaluating a condition of an interior surface of a
gas turbine combustor and transition duct, comprising: creating a
sequence of comprehensive images of the interior surface over a
respective time sequence of successive digital camera inspections
of the gas turbine combustor; generating by computer a set of color
and shading intensity contours on each of the comprehensive images;
identifying and tracking by computer ones of the contours over
successive ones of the comprehensive images; plotting a time series
of a size of each tracked contour; and evaluating by computer the
time series for indications of degradation of the interior
surface.
11. The method of claim 10, further comprising providing a
computerized alert when an acceleration of a degradation rate is
found in the time series.
12. The method of claim 10, further comprising performing
computerized identification of aspects of size, gradient, shape,
and overlap of the contours, and computerized analysis of said
aspects for the indications of degradation of the interior
surface.
13. The method of claim 10, further comprising forming each
comprehensive image by obtaining a circumferential sequence of
photographs around a circumference of the interior surface at each
of a sequence of axial positions along a 3D centerline of the
interior surface; and digitally stitching the photographs
together.
14. The method of claim 13, further comprising; removing a pilot
fuel nozzle from a pilot fuel port of the gas turbine combustor;
inserting a scope into the combustor via the pilot fuel port;
rotating a camera on a distal end of the scope around the
circumference of the interior surface at each of the sequence of
axial positions to obtain each circumferential sequence of
photographs.
15. The method of claim 13, further comprising defining a
three-dimensional geometry of the interior surface by scanning the
interior surface with a 3D surface scanner in the distal end of the
scope, and digitally modeling the interior surface in three
dimensions by mapping the comprehensive image onto the
three-dimensional geometry of the interior surface creating a
digital visual model of the interior surface in a computer for
interactive viewing.
16. The method of claim 15 further comprising performing
computerized analysis of a degree of a roughness of the interior
surface as defined by the 3D scanner.
17. A method for evaluating a condition of an interior surface of a
component in a gas flow path of a gas turbine, comprising: forming
a comprehensive image of the interior surface over a circumference
and a length thereof by digitally stitching a plurality of
individual images of the interior surface obtained from a device on
a scope inserted into the component; and determining the condition
of the interior surface by creating contours of colors in the
comprehensive image and analyzing the contours thereof for
indicators of the condition of the interior surface.
18. The method of claim 17, further comprising: before forming the
comprehensive image, painting the interior surface with a thermal
imaging paint, and starting and running the gas turbine; and
stopping the gas turbine, and forming the comprehensive image.
Description
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/972,000, filed 21 Aug. 2013 and published
as US 2013/0335530 A1 (attorney docket 2013P09381 US), which is
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to internal inspection of machinery,
and more particularly to internal imaging and evaluation of power
generating components including gas turbine combustor baskets and
transition ducts.
BACKGROUND OF THE INVENTION
[0003] Internal surfaces of gas turbine combustors and transition
ducts have been inspected using a scope camera inserted through the
pilot nozzle port after removal of the pilot nozzle. This provides
access for the scope through the center of the combustor cap into
the combustion chamber basket and transition duct. However,
previous camera inspection systems produce on the order of 300
individual photos of the interior surfaces of each combustor
basket/transition. Position data may be stored with each image, but
it is difficult and time consuming to make comparisons among these
numerous small overlapping images in order to visualize the
interior surface topography and any coloration or shading changes
over larger areas than each individual photo. Visualization is
complicated by the non-cylindrical shape of transition ducts, which
causes image distortion from the angles of the inner surface
relative to the camera.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The invention is explained in the following description in
view of the drawings that show:
[0005] FIG. 1 is a partial side sectional view of a gas turbine
engine known in the art.
[0006] FIG. 2 is a perspective view of a transition duct known in
the art.
[0007] FIG. 3 is side sectional view of an inspection scope
inserted into a gas turbine combustor according to aspects of an
embodiment of the invention.
[0008] FIG. 4 is side sectional view of an inspection scope
inserted into a gas turbine combustor and transition duct according
to aspects of an embodiment of the invention.
[0009] FIG. 5A is a sequence of photos taken around the
circumference of the interior surfaces of a combustor basket and
transition duct at a given axial position.
[0010] FIG. 5B is a circumferential panoramic image created by
stitching the photos of FIG. 5A together.
[0011] FIG. 5C is a series of circumferential panoramic images as
in FIG. 5B taken at successive axial positions in the combustor
basket and transition duct.
[0012] FIG. 5D is a comprehensive image formed by stitching the
circumferential panoramic images of FIG. 5C together.
[0013] FIG. 6 is a size history of three intensity contours tracked
over time.
[0014] FIG. 7 is an enlarged side sectional view of the end of the
scope of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 is a partial side sectional view of a gas turbine
engine 20 with a compressor section 22, a combustion section 24,
and a turbine section 26 as known in the art. One of the combustors
28 of a circular array of combustors in a can-annular arrangement
is shown. Each combustor 28 has an upstream end 30 and a downstream
end 32. A transition duct 34 and an exit piece 35 thereof transfer
the combustion gas 36 from the combustor to the first row of
airfoils 40 of the turbine section 26, which includes stationary
vanes and 38 rotating blades 40. Compressor blades 42 are driven by
the turbine blades 40 via a common shaft 41. Fuel 42 enters each
combustor via a central pilot fuel nozzle 43, and via other supply
tubes to a circular array of premix injectors. Compressed air 45
enters a plenum 46 around the combustors. It enters the upstream
end 30 of the combustors, and is mixed with the fuel therein for
combustion. The compressed air 45 also surrounds the combustors 28
and transition ducts 34 to provide cooling air thereto. It has a
higher pressure than the combustion gas 36 in the combustor and in
the transition duct.
[0016] FIG. 2 shows a transition duct 34 with an upstream end 48
that receives combustion gas 36 from the combustor. The upstream
end 48 may be cylindrical. The downstream end 49 may be
non-cylindrical such a generally rectangular. The duct body may
have a substantial curvature 50.
[0017] FIG. 3 is sectional side view of a combustor 28 with support
legs 52, between which compressed air 45 (FIG. 1) enters to mix
with fuel that is supplied to premix injectors 53 via fuel ports 54
in a mounting plate 55. Some detail is omitted for clarity,
including supply lines to the fuel ports. A central fuel port 56
receives a pilot fuel nozzle 43 (FIG. 1), which is removed here. In
its place, a camera boom or scope 58 is inserted for internal
inspection of the combustor basket 59 and transition duct. Details
of such camera systems are provided in the parent US patent
application.
[0018] An inspection system housing 60 may be mounted to the pilot
fuel port 56 by a mechanism normally used to mount the pilot fuel
nozzle--for example by a threaded collar and/or machine screws 57.
A scope positioning drive 62 may include a scope rotation drive 63
and translation drive 64. The rotation drive is optional if the
distal end of the scope rotates as later described. A
computer/controller 66 may control these drives. An interactive
computer station 65 may provide operator control and computer
graphics for human analysis. Control signal lines and power
conductors may be provided through the interior of the scope.
Control and power lines 67 may be provided to one or more cameras,
lights, and distal actuators in the scope. Such lines 67 may
include electrical conductors and, in some embodiments, optical
fibers. The combustor 28 as shown is illustrated for reference, and
is not a limitation except as claimed.
[0019] FIG. 4 is a sectional view of a scope 58 mounted as shown in
FIG. 3, inserted into and through a combustor 28 and transition
duct 34. The scope may have one or more motor controlled
articulations 68, such as detailed in the parent US patent
application. The end 70 of the scope may be rotatable by a motor 71
for scanning and imaging 360 degrees around the circumference of
the inner surfaces 78, 80 at a given axial position. Herein "axial
position" means a position along the axis 75 of the distal portion
70 of the inspection scope, which may substantially align with the
3D geometric centerline of the interior surfaces 78, 80 as much as
possible. The end portion 70 may enclose a device such as camera
72, and may further include a lens 74 such as a galvanometer
actuated mirror that pivots on an axis normal to the axis 75 of the
end 70 of the scope. One or more lights 76 may be provided for the
camera. Other embodiments are taught in the parent US patent
application.
[0020] FIGS. 5A-D illustrate a process of stitching photos of the
inner surfaces 78, 80 into a comprehensive view for analysis. FIG.
5A is a sequence or set 84 of photos 82 taken around the
circumference of the interior surfaces of a combustor basket and
transition duct at a given axial position. FIG. 5B is a
circumferential panoramic image 86 created by stitching the photos
82 of FIG. 5A together. FIG. 5C is a series of circumferential
panoramic 86 images as in FIG. 5B taken at successive axial
positions in the combustor basket and transition duct. FIG. 5D is a
comprehensive image 87 formed by stitching the circumferential
panoramic images of FIG. 5C together and eliminating overlaps. This
comprehensive image visually clarifies aspects of the surfaces that
are unclear in the individual photos 82. For example, darker shaded
areas 88 may indicate normal carbon deposits. Lighter areas 89
within a dark area may indicate a hot spot where carbon is burned
away. Although not visible in black and white, a diffuse yellow
coloration is present, especially in the dashed area 91 shown,
which may indicate oxidation. Another area 95A has a slight blue
tint with a slightly higher intensity in area 95B. Such colorations
and shadings may be contoured by computer for analysis.
[0021] An engineering model of the combustor assembly may be used
to identify and image features caused by structures such as
crosslink tubes 85, acoustic damper holes 90, and film cooling
holes 92, and subtract/ignore such features when creating surface
contours 89, 90, 91, 95A-B. Alternately, the structural features
85, 90, 92 may be contoured in addition to the surface contours so
that changes in shape or position of the structures can be
analyzed. Static analysis of the comprehensive image may be
performed based on absolute intensity limits, contour gradient
limits, contour jaggedness, and contour overlaps--for example, a
white area overlapping grey or grey overlapping yellow. The
contours may be tracked over successive inspections. Quantified
aspects of the tracked contours may be graphed in a time series to
show the rates and accelerations of degradation as later shown.
This analysis may be used to adjust or preempt a maintenance
schedule. In general, shading and colors may be analyzed to
indicate wear and condition characteristics of the gas path
surfaces, including any thermal barrier coating thereon. A jagged
contour may indicate exfoliation or spelling of the thermal barrier
coating due to age, environment, structural flaws, or
overheating.
[0022] In another method utilizing the invention, a thermal
indicator paint may be applied to the inner surfaces 78, 80 prior
to assembling the combustor section, either in original production
or after disassembly for maintenance. A test run of the engine may
be performed for a limited time to bring the surfaces to operating
temperatures. The engine may then be shut down, and the inner
surfaces examined in accordance with the present invention. The
thermal paint will then display the heat topography at the
operating temperatures as a color topography. This indicates
whether a new engine design, or a maintenance re-assembly, or a
modification meets specifications for thermal limits, and if an
engine is operating properly. By using the present invention, there
is no need to disassemble the combustors to inspect the thermal
paint response. Subsequently, after a period of engine operation,
the thermal paint burns away, and the previously described time
series of inspections may be performed without thermal paint.
[0023] FIG. 6 illustrates a time series of the sizes of three
different intensity contours A, B, and C over a sequence of
inspections. Contour A shows normal wear, Contour C shows no wear
or degradation. Contour B shows a recent acceleration 89 in
degradation above a predetermined acceleration threshold, causing
an automated alert from the computer. The individual contours A, B,
C may be identified and tracked over time using known algorithms,
for example as used for weather radar tracking of storm cells and
their intensities over time to compute local rainfall. The shapes
of such contours may be quantified in terms of jaggedness, aspect
ratio, or other factors. Such quantifications allow a high degree
of automatic analysis that can bring timely attention to particular
areas by computerized alerts, which may be presented for example as
an audible alert and a flashing contour.
[0024] FIG. 7 shows an enlarged side sectional view of the distal
end 70 of the scope 58 of FIG. 4. A camera sensor 72 such as a
charge coupled device or other image sensor receives an image
directed from a galvanometer-controlled mirror 74. A light source
76 projects a pattern 92 onto the inner surface 80 of the
transition duct 34 for surface definition by the
computer/controller as described in the parent US patent
application. A liquid crystal panel 93 in the light/projector 76/93
may define the pattern and alternately clear to allow non-patterned
light to illuminate the surface for photography as in FIG. 5A.
Alternately, separate lights may be provided for pattern projection
and photographic illumination. Surface scanning defines a precise
surface contour relative to the camera for each image 82. The
surface 80 can be accurately reconstructed in three dimensions as a
digital model by known pattern projection and triangulation between
the projector and the receiving mirror or lens 74. The photographic
illuminating light may be white and/or a succession of different
colors to enhance respective different aspects of the surface 80.
As an alternative to a pattern projector 93, a triangulating laser
surface scanner may be provided for defining the surface 80 in
three dimensions. Such scanners can image a surface in 3 dimensions
to a precision of tens of microns or thousandths of an inch, and
thus can define surface roughness as an additional aspect of the
comprehensive image for analysis.
[0025] By defining the surface relative to the camera, distortions
due to camera angle can be removed by known algorithms. The surface
image can then be transformed into a digital 3D visible surface
rendering using known algorithms, allowing human inspectors to
interactively "walk through" the combustor basket and transition
duct via computer graphics for inspection, which may be color
enhanced. An exemplary 3D scanning image processing software
program is the "MeshLab" package of open source software that is
downloadable via the Internet from the National Research Council of
Italy Visual Computing Lab. Another source for exemplary 3D
scanning image processing software is Geomagic of Research Triangle
Park, N.C., USA.
[0026] In one embodiment, the comprehensive image may be mapped
onto an engineering model of the interior surface to create a
digital visual model of the interior surface in a computer for
interactive walk-through viewing. Image distortions due to camera
angle may be removed by defining the surface angles with a surface
scanner as previously described and/or by fitting the comprehensive
image to known surface features in the engineering model such as
holes in the surface.
[0027] While various embodiments of the present invention have been
shown and described herein, it will be obvious that such
embodiments are provided by way of example only. Numerous
variations, changes and substitutions may be made without departing
from the invention herein. Accordingly, it is intended that the
invention be limited only by the spirit and scope of the appended
claims.
* * * * *